Conventionally, a random number sequence obtained from a simple random number algorithm, such as M-sequence, has high randomness in a one-dimensional direction. When R number of one-dimensional random number sequences each having C number of elements are prepared while their initial values are varied and the sequences are arranged in a two-dimensional manner like R×C, if the Hamming distance between the initial values in the adjacent rows is small, the obtained random number sequences are in correlation and the numbers in the random number sequence in the column direction are biased to 0 or 1. In some cases, all of the R number of sequences are 0 or 1, which results in poor randomness.
However, in a conventional technique, when the randomness is increased in the two-dimensional arrangement, a problem occurs in that the circuit scale is increased.